'Twilight' actor Cam Gigandet filming comedy in Chicago

Cam Gigandet has been having a difficult time explaining the unusual premise of the independent adult comedy he's currently filming in Chicago — as would most people.

The “Twilight” and “Never Back Down” actor plays a womanizing bachelor who wishes he didn't have his, er, manhood after his promiscuity lands him in trouble. When he gets his wish (in a strange way), he ends up questioning whether there's more to life than bed-hopping.

“It takes a minute (to explain),” Gigandet said over the phone Saturday from the set of “Johnson.” “I try to explain it very carefully. … Some will think it's stupid. Hopefully more will find it funny.”

What attracted Gigandet to such an odd script?

“This is my first comedy,” said Gigandet, who filmed “The Unborn” and “5 Star Day” in the Chicago area. “I was up for the challenge. I wanted to do a comedy, and this was right up my alley — my kind of silly humor. I wasn't going to jump onto a Vince Vaughn movie. This one, I felt like I could be myself and have fun without too much pressure.”

Filming began in the city Wednesday and is scheduled to wrap up Oct. 31. According to producer Danny Roman, the comedy has so far shot at the Opera Lofts in the South Loop, The Charleston bar in the Bucktown neighborhood, Empire Liquors in Wicker Park and People Play Games in Lakeview. A wedding scene is scheduled to shoot Oct. 22 at Lincoln Park Conservatory.

Asked why Chicago was chosen as the location, Roman pointed to the city's film tax break and said fellow producer Bill Ryan enjoyed working with late director John Hughes on his Chicago-area movies.

“Johnson” co-stars comedian Nick Thune and is directed by Huck Botko, who helmed “The Virginity Hit.” Newcomer Jeff Tetreault wrote the script and has called the story semi-autobiographical. He can explain.

“The idea was inspired by a five-year relationship,” Tetreault said by email. “I was dating a girl that I deeply loved, but our sex life had become almost nonexistent. It was crazy to me that I could care about someone so much but not really be into them physically anymore. I felt like two different people. Exploring the theme of love versus sex, heart versus anatomy, laid the foundation for the script.”